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Commit d8dca330 authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Jonathan Cameron
Browse files

staging:iio:ad799x: Preallocate sample buffer 



Avoid allocating and freeing the sample buffer for each transfer. Instead
allocate it once when we start sampling. Also pre-compute the number of bytes we
need to transfer in the same way.

Signed-off-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent d00698df

drivers/staging/iio/adc/ad799x.h

+3 −0
Original line number Diff line number Diff line
@@ -106,6 +106,9 @@ struct ad799x_state { 
	u16				int_vref_mv;

	unsigned			id;

	u16				config;



	u8				*rx_buf;

	unsigned int			transfer_size;

};



/*

drivers/staging/iio/adc/ad799x_core.c

+8 −0
Original line number Diff line number Diff line
@@ -104,6 +104,13 @@ static int ad7997_8_update_scan_mode(struct iio_dev *indio_dev, 
{

	struct ad799x_state *st = iio_priv(indio_dev);



	kfree(st->rx_buf);

	st->rx_buf = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);

	if (!st->rx_buf)

		return -ENOMEM;



	st->transfer_size = bitmap_weight(scan_mask, indio_dev->masklength) * 2;



	switch (st->id) {

	case ad7997:

	case ad7998:
@@ -665,6 +672,7 @@ static int ad799x_remove(struct i2c_client *client) 
		regulator_disable(st->reg);

		regulator_put(st->reg);

	}

	kfree(st->rx_buf);

	iio_device_free(indio_dev);



	return 0;

drivers/staging/iio/adc/ad799x_ring.c

+4 −12
Original line number Diff line number Diff line
@@ -36,14 +36,9 @@ static irqreturn_t ad799x_trigger_handler(int irq, void *p) 
	struct iio_dev *indio_dev = pf->indio_dev;

	struct ad799x_state *st = iio_priv(indio_dev);

	s64 time_ns;

	__u8 *rxbuf;

	int b_sent;

	u8 cmd;



	rxbuf = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);

	if (rxbuf == NULL)

		goto out;



	switch (st->id) {

	case ad7991:

	case ad7995:
@@ -66,20 +61,17 @@ static irqreturn_t ad799x_trigger_handler(int irq, void *p) 
	}



	b_sent = i2c_smbus_read_i2c_block_data(st->client,

			cmd, bitmap_weight(indio_dev->active_scan_mask,

					   indio_dev->masklength) * 2, rxbuf);

			cmd, st->transfer_size, st->rx_buf);

	if (b_sent < 0)

		goto done;

		goto out;



	time_ns = iio_get_time_ns();



	if (indio_dev->scan_timestamp)

		memcpy(rxbuf + indio_dev->scan_bytes - sizeof(s64),

		memcpy(st->rx_buf + indio_dev->scan_bytes - sizeof(s64),

			&time_ns, sizeof(time_ns));



	iio_push_to_buffers(indio_dev, rxbuf);

done:

	kfree(rxbuf);

	iio_push_to_buffers(indio_dev, st->rx_buf);

out:

	iio_trigger_notify_done(indio_dev->trig);